I have been playing Thunderstone a bit online and really like it. I am in the process of trading for the base game and was wondering if I could get a little help with all the expansions for the game. I would really like to get the most out of thunderstone, but there are so many expansions I have no idea where to start!

I would recommend getting Thunderstone Advance instead. I have Tstone and most of the expansions, and they each bring their own flavor and they are quire fun, but I think the newer editions are significantly better if you can them!

If you wanted to stick with the original, I'd get either Dragonspire as previously mentioned by others, otherwise Heart of Doom was also good.
I'd probably get Doomgate Legion and Thornwood Siege last.

Oh, my bad. I only have Towers of Ruin and Caverns of Bane, didn't get Root of Corruption yet. You need ToR to start, it's the new base set essentially. Not all the original TStone cards work in the new system, but most do.

Note that the monsters are organized differently. Instead of randomly picking 3 groups of monsters, they now organize them as level 1/2/3 categories. You then pick a monster type from level 1, another from level 2 and another from level 3. It gives you a more balanced dungeon deck.

They released a handy compatibility table to use:
Here!
Hope this helps!

It was designed to be an entry level product. It's a "stand-alone expansion to Thunderstone. The cards within can be played with any or all of the past Thunderstone sets, or can be used by themselves as a fully playable set".

So technically an expansion but it's basically the full game, balanced and ready to expand further. The box includes all the storage and storage labels you'll need once you start including any other expansion packs.

Dragonspire was the set I started with when asking almost the same question as you did. I don't regret getting it.

Get Thunderstone Advance instead. They tweaked some of the base rules to make the game go quicker and provoke players to gamble a little bit in the dungeon. It makes the game more dynamic and fun, helping to fix the early game stall while you're in the village buying heroes the first several turns. The base cards from the original base set (militia, torch, dagger, iron rations) were overhauled so they're worthless, however all of the weapons, heroes, monsters, and village cards are different so you can consider Advance an expansion in that respect.

Regular + spear = draw a card in the dungeon. It's the way they tried to curb the early game stall. If you go into the dungeon only one away from beating a monster, you roll the dice by drawing and hope for another regular or spear